Locking mechanism for well drilling rotary



A. R. MAIER Dec. 29, 1942.

LOCKING MECHANISM FOR WELLI- DRILLING ROTARY Filed April '24, 1941 lmenfm': & 406057' E. Mam-e, LL %A 5 Patented Dec. 29, 1942 hurrah srrrs LOCKING MECHANISM FOR WELL DRILLING ROTARY August R. Maier, Oil City, Pa., assignor to Oil Well Supply Company, a corporation of New Jersey Application April 24, 1941, Serial No. 390,172 I 5 Claims. 7 (Cl. 18869) This invention relates to improvements in a locking mechanism for well drilling rotaries adapted to lock the rotary table against rotation as when making up or breaking out the drill pipe joints, etc.

Among the objects of my invention are to pro k vide a locking means capable of securing the rotary against rotation in either direction; to provide for the complete enclosure of the actual locking engagement against foreign matter and hazard to the workmen; to provide for the positive automatic return of the mechanism to unlocked position upon release by the operator; and to provide a simple, positive locking mechanism of the character stated having a minimum number of parts.

Additional objects and advantages will become apparent from the following description, taken in connection with the accompanying drawing, wherein:

Fig. 1 is an elevational and part sectional view of a well drilling rotary embodying my invention; 4

Fig. 2 is a plan view partly in section of a portion of Fig. 1; and

Fig. 3 is an enlarged sectional view taken along the line IIIIII of Fig. 1, the outer bearing mounting being removed for clearness.

Referring to the drawing, 2 designates a rotary table rotatably mounted on a base 3 and having a table gear 4 driven by a pinion 5 from pinion shaft 6. A housing 1 encloses the pinion shaft with an end of the latter projecting therefrom for attachment with a suitable source of power, as by means of a sprocket 8.

For the purpose of locking the rotary table 2 against movement in either direction and thereby holding the drill pipe stationary as when breaking out joints, I provide locking means in connection with the pinion shaft 6- including a locking wheel a secured to the shaft within the housing 7, said wheel having a plurality of spaced peripheral notches I each having opposed inwardly extendlng locking faces ll.

At one side of the rotary, I provide a rock shaft 12 spaced from and parallel to the pinion shaft, the rock shaft l2 being rotatably supported in an inner bearing [3 and extending outwardly through and beyond a bearing I l in the end wall of the housing 1. A locking pawl or dog i is secured to the shaft I2 within the housing and has a terminal detent l6 designed to engage the notches H] in the locking wheel 9. The detent portion 16 coacts with the faces I l of said notches so as to prevent rotation of the locking wheel and the table 2 through the meshing gears 3 and 5.

In order that the driller may actuate the pawl I5 in an expeditious manner from a point outside the housing 1, a foot pedal ll is secured to the extending end of the rock shaft 52, said pedal having a weighted or counterbalance portion is designed to normally rotate the pedal, shaft and pawl outwardly to maintain said pawl out of engagement with its locking wheel 9, as shown in dotted lines in Fig. 3, the upper rear portion 59 of the pawl l5 engaging the wall of the housing I to limit the releasing movement of said mechanism. While the magnitude of the weight It and its angular position relative to the pawl it are 7 sufficient to overbalance said pawl and normally retract the latter, a spring 20 may be provided, connected with the pawl at 2| and to the inner wall of the housing 1 to insure a quick retraction of the pawl when unlocking the rotary.

A latch 22 is pivotally mounted on the exterior of the housing 1 above the pedal I1, and has 21 depending foot 23 engaging the housing to nor-- mally dispose an overhanging lip 2 of the latch in interfering position with respect to the travel of a ccacting apertured terminal 25 of the pedal.

The outer edge 25 of the latch lip is in the form' of a cam, so that when the same is en aged by the terminal 25, the lip is elevated to over-ride the terminal and finally gravitate about its pivot downwardly into a receiving aperture 2i to automatically secure the pedal in elevated position at the time of engagement of the pawl detent it with one of the notches of the locking wheel 9. Hence, the rotary may be secured in locked position until the latch 22 is released to permit gravitational return of the pedal and pawl.

The latch 22 has an upper free terminal 2% which may be engaged by the foot of the operafor to release said latch from the pedal. Also, the upper foot-engaging face 29 of the pedal 5'? is provided with a guard abutment or lug 3t preventing the toe of the operator from being pinched between the latch and pedal when engaging the same.

By the foregoing mechanism, I am enabled to lock the rotary against rotation in either direction of rotation and to positively maintain said locked position as long as is desired. Also, by tripping the latch 22 and taking the load off the pawl and locking wheel engagement, as by a slight rotation of the table 2, the locking pawl l5 will be automatically retracted by the gravitational movement of the pedal l'i, assisted by pinion shaft in either direction, thereby locking the sp ant:

Due to the complete enclosure of the locking wheel and pawl within the housing 1, the same are free from dirt, water, etc., and are completely guarded against fouling the operator during use 'of the rotary. Various changes and modifications are contcmplated within the scope of the following claims.

I claim:

1. A rotary locking device of the character described, including a notched locking Wheel secured to the means for driving the table of the rotary, a single pawl pivoted for movement into engagement with the wheel notches, a foot pedal movable with said pawl and having a weighted portion normally displacing the pawl out of engagement with said wheel, said foot pedal also having an apertured portion, a pivoted latch normally disposed in interfering position with relation to the movement of the apertured portion of the pedal, said latch having a lip engaging the pedal aperture upon movement of the pawl into a Wheel notch by the pedal, thereby securing the mechanism in locked position. 7

2. A rotary locking device of the character described, including a notched locking wheel secured to the means for driving the table of the rotary, a single pawl pivoted for movement into engagement with the wheel notches, a foot pedal movable with said pawl and having a weighted portion normally displacing the pawl out of engagement with said wheel, said foot pedal also having an apertured terminal, a pivoted latch having a lip and a camportion normally disposed in interfering position with the movement of the apertured terminal, the cam portion being shaped to elevate the latch upon engagement by said terminal and permit the lip to engage the aperture upon the entrance of the pawl in a wheel notch, thereby securing the mechanism in locked position.

3. In a rotary having a table and a pinion shaft therefor, a housing enclosing the pinion shaft, means for locking the rotary table against rotation in either direction by locking said pinion shaft, including a locking wheel secured to the shaft within the housing, said wheel having a plurality of notches therein, a pivot shaft extending through the housing, a single pawl secured thereto within the housing and a foot pedal secured thereto externally of the housing, said pawl being movable with the pedal and pivot shaft to selectively engage the Wheel notches, said pedal being counterbalanced for normally positioning the pawl out of engagement with the Wheel notches, and a pivoted latch externally of the housing, said pedal and latch having c0- acting interengaging means automatically securing the pedal upon movement of the latter a sufficient amount to enter the pawl in a wheel notch.

4. A rotary locking device of the character described, including a notched locking wheel secured to the means for driving the table of said rotary, a single pawl pivoted for movement into engagement with the wheel notches, said pawl and wheel notches having coacting means preventing rotation of the wheel in either direction, a foot pedal movable with said pawl, a counterbalance on said pedal normally displacing the pawl out of engagement with the wheel, and a pivoted latch actuated by the foot pedal, said pedal and latch having coacting interengaging portions automatically securing the pedal in locked position upon engagement of the pawl with a wheel not'ch.

5. A rotary locking device of the character described, including a locking wheel secured to the means for driving the table of said rotary, a single pawl pivoted for movement into engagement with the Wheel, a foot pedal movable with said pawl, a counterweight normally displacing the pawl out of engagement with the wheel, said wheel having a plurality of notches and said pawl having a detent, the notches and detent coacting when engaged to prevent rotation of the Wheel in either direction, and a pivoted latch actuated by the foot pedal, said pedal and latch having coacting interengaging portions automatically securing the pedal in locked position upon engagement of the pawl with awheel notch.

AUGUST R. MAIER. 

